Ghost Pictures: Return of a Friend

This ghost picture is strange to say the least. It was supposed to be of the photographers daughter. Instead it captured what appeared to be a haunting face. The ghost face was strikingly similar to that of the photographers close friend, who had recently been killed. A picture of that friend is there for comparison. Could this be the same friend that had been killed? Was he watching over the ones he cared for? Or is it simply an illusion?